Introduction to Datawarehouse

The term “Data Warehouse” was first coined by Bill Inmon in 1990. He said that Datawarehouse is subject Oriented, Integrated, Time-Variant and nonvolatile collection of data.This data helps in supporting decision making process by analyst in an organization.

Characteristics of Datawarehouse:

The key features of Data Warehouse such as Subject Oriented, Integrated, Nonvolatile and Time-Variant are discussed below:

Subject Oriented – The Data Warehouse is Subject Oriented because it provide us the information around a subject rather the organization’s ongoing operations. These subjects can be Sales, Marketing, Finance etc.

Integrated – Data Warehouse is constructed by integration of data from heterogeneous sources such as relational databases, flat files etc. This integration enhances the effective analysis of data.

Time-Variant – The Data in Data Warehouse is identified with a particular time period. The data in data warehouse provide information from historical point of view.

Non Volatile – Non volatile means that the previous data is not removed when new data is added to it. The data warehouse is kept separate from the operational database therefor frequent changes in operational database are not reflected in data warehouse.

Data Warehouse helps the business executives in organize, analyze and use their data for decision making.Data Warehouse is widely used in the following Domains: